For example, a light adjuster which is sandwiched between a plurality of glass sheets to control the amount of light transmitted through the glass sheets is usually comprised of a liquid crystal layer, and a pair of sheets (PET films) each having a transparent electrically conductive film formed thereon, which sandwich the liquid crystal layer therebetween.
The liquid crystal layer includes liquid crystal molecules whose orientation is changed by voltage application, and is capable of controlling the amount of light transmitted according to changes in the orientation of the liquid crystal molecules caused by voltage applied to the liquid crystal layer from the pair of transparent electrically conductive films.
In manufacturing the light adjuster, first, the liquid crystal layer is formed on the transparent electrically conductive film of one of the PET films, and then the other PET film having the transparent electrically conductive film is stuck onto the liquid crystal layer thus formed such that the transparent electrically conductive film of the other PET film contacts the formed liquid crystal layer. This sequence of operations is performed in succession, and the light adjuster thus manufactured is in the form of a long sheet.
The light adjuster thus manufactured is used either alone or in the form of a laminated glass in which the light adjuster is sandwiched between a plurality of glass sheets. However, there are various sizes of windows and doors into which the light adjuster is to be fitted either alone or in the form of a laminated glass, and hence the light adjuster used alone or in the form of a laminated glass is required to be in various sizes.
On the other hand, to supply electric power to the transparent electrically conductive films of the light adjuster, the light adjuster is provided with electrode terminal sections connected to the transparent electrically conductive films and having lead wires for receiving electric power supplied from the outside. Generally, in housing the light adjuster or the laminated glass with the light adjuster sandwiched between the glass sheets, for example, terminals of an external power supply which supplies electric power to the lead wires of the electrode terminal sections are disposed inside e.g. a sash which holds the periphery of the light adjuster or the laminated glass in consideration of the appearance of the housed light adjuster or laminated glass, and hence the electrode terminal sections need to be disposed at the periphery of the light adjuster.
For this reason, it is configured such that the liquid crystal layer and transparent electrically conductive films can be peeled or stripped off at arbitrary positions thereof so that the light adjuster in the form of a long sheet can be cut out in a size corresponding to an area for use (such as a windrow or a door), then a part of the liquid crystal layer at a position where the light adjuster is to be housed is removed, and parts of the transparent electrically conductive films at this position can be provided with electrode terminal sections.
In this light adjuster, the force required for stripping the liquid crystal layer off is controlled to be as low as possible, i.e. not greater than 10 g/cm due to requirements for improvement of workability.
However, there is the following problem with the prior art: In fitting a light adjuster alone into a window or a door with the periphery of the light adjuster being supported, a force is concentrated at the periphery of the light adjuster since the periphery is supported, or in manufacturing a laminated glass with a light adjuster sandwiched between a plurality of glass sheets, a force is concentrated at the periphery of the light adjuster due to adhesion of the glass sheets and the light adjuster, and if the force for stripping the light adjuster off is set to be not greater than 10 g/cm due to the above-mentioned requirements for improvement of workability, the transparent electrically conductive films and the liquid crystal layer can exfoliate on the market due to the shortage of the stripping force, and then the portion of the light adjuster where the exfoliation occurs becomes cloudy.
On the other hand, if the force required for stripping off is set to be excessively high, the workability in stripping the liquid crystal layer off is degraded, and partial exfoliation of the transparent electrically conductive films can occur, resulting in a degraded yield.
It is therefore an object of the present invention to provide a light adjuster and a laminated glass which are free from occurrence of cloudiness, and can maintain sufficient workability to improve the yield.